Whitening Sensitivity

Why Do Teeth Become Sensitive After Whitening?

Whitening gel contains hydrogen peroxide, or carbamide peroxide, which releases hydrogen peroxide in the mouth. To lighten the tooth, the peroxide has to travel through the enamel into the dentine beneath, where much of the colour sits. Dentine is full of microscopic channels that lead towards the pulp, the soft tissue in the centre of the tooth that contains the nerve.

As the peroxide passes through, it can mildly irritate the pulp. The result is a tooth that reacts more than usual to cold, heat, sweet things or air, or that gives occasional sharp twinges for no obvious reason.

In most people this irritation is short-lived and reversible. Once the gel stops, the pulp settles and the sensitivity fades. Used as directed with custom trays, professional whitening isn't known to cause lasting harm to healthy teeth.

How Common Is It, and How Long Does It Last?

Sensitivity is the most common side effect of tooth whitening. Many people notice at least some, and for most it's mild: an awareness of cold drinks or a brief twinge rather than ongoing pain. A smaller number find it uncomfortable enough to pause their course.

When it starts. It usually appears within the first few days of whitening, and may come and go during the course.

How long it lasts. It typically eases within a day or two of stopping the gel, and nearly always within a few days. If it carries on for longer than that, it's worth getting your teeth checked, because something else may be going on.

Everyone reacts differently, so it's hard to predict how your own teeth will respond until you start. That's one reason we review how you're getting on rather than setting a fixed routine and leaving you to it.

What Does Whitening Sensitivity Feel Like?

People describe it in a few ways:

• a sharper reaction to cold, such as cold water, ice cream or breathing in cold air on a winter morning in Edinburgh
• short, sudden twinges, sometimes called zingers, that shoot through one or more front teeth for a second or two and then pass
• a dull ache across several teeth, often after a longer session with the trays

It usually affects the teeth that are being whitened, often the front ones, and tends to feel similar on both sides. Pain that is focused on one tooth, keeps you awake or throbs on its own is different, and is covered further down.

Who Is More Likely to Get Sensitivity?

Some people are more prone to it than others. You're more likely to notice sensitivity if you have:

• teeth that are already sensitive before you start
• receding gums, where the root surface is exposed and has no enamel covering it
• worn enamel from grinding, brushing too hard or acidic food and drink
• small cracks in the teeth, or decay
• old fillings with gaps around the edges

This is why we examine your teeth and gums before whitening. Decay, leaking fillings and active gum problems are treated first, both for comfort and because whitening can hide problems rather than fix them. If you already have sensitive teeth, we'll plan the course around it from the outset rather than waiting to see what happens. You can find out more about how whitening works on our teeth whitening page.

How Can You Reduce Sensitivity During Whitening?

Most sensitivity can be kept to a comfortable level with a few adjustments. These are the ones we use most.

Desensitising toothpaste. A toothpaste containing potassium nitrate, used twice a day for about two weeks before you start and throughout the course, calms the nerve response. Some people also put a little in their trays for 10 to 30 minutes before whitening. Toothpastes that block the dentine channels, such as those containing stannous fluoride, are another option.

Less gel. Use only the small amount we show you. Overfilling the trays doesn't whiten faster; it just pushes gel onto the gums and increases irritation.

Shorter wear time. If overnight wear is uncomfortable, you can switch to a shorter session during the day. Whitening simply takes a little longer.

Gaps between sessions. Whitening every other night, or taking a night or two off when teeth feel tender, gives the pulp time to settle. The final result is usually much the same; it just takes a few more days to get there.

A lower-strength gel. If needed, we can supply a gentler gel. Again, the trade-off is time rather than result.

Day-to-Day Comfort While You're Whitening

Alongside the changes above, a few everyday habits make a difference:

• choose lukewarm drinks rather than very hot or iced ones during the course
• cut back on acidic food and drink, such as citrus, fizzy drinks and wine, which can make sensitivity worse
• brush with a soft brush and gentle pressure, and don't scrub along the gumline
• spit out toothpaste after brushing rather than rinsing, so the active ingredients stay on your teeth
• if you need pain relief, ordinary over-the-counter painkillers, taken as directed on the packet, usually help

If you're unsure whether a particular painkiller is suitable for you, check with a pharmacist.

Sore or White Gums After Whitening

Not all discomfort comes from the teeth. If gel leaks out of the tray, it can irritate the gums, causing soreness or small white patches along the edge of the gum. These usually fade within a few hours and heal without any treatment.

To avoid it, use less gel, wipe away any that squeezes out with a clean finger or a tissue, and make sure the trays are seated properly. If gum irritation keeps happening in the same spot, the tray may need trimming, so bring it in and we'll adjust it. Gum soreness that lasts several days, or ulcers that don't heal within about two weeks, should be checked by a dentist.

When Should You Stop Whitening and Call Us?

Stop using the gel and contact the practice if:

• sensitivity is severe, or doesn't ease after taking a few nights off
• it carries on for more than a few days after you've stopped whitening
• the pain is in one tooth rather than spread across several
• you have throbbing pain that starts on its own or keeps you awake
• a tooth is tender to bite on, or you notice swelling of the gum or face
• your gums are blistered or ulcerated

These signs can point to something other than ordinary whitening sensitivity, such as a crack, a leaking filling, decay or an inflamed nerve. They're unusual, but they need checking rather than pushing through.

We're open Monday to Friday, 9am to 5.30pm, and keep emergency appointments for patients in pain. If you have facial swelling that is spreading, or difficulty swallowing or breathing, seek urgent medical help straight away. Out of hours, NHS 24 on 111 can advise.

Does Sensitivity Mean Whitening Isn't for You?

Rarely. Most people who notice sensitivity still complete their course, simply with more breaks or shorter sessions. People with known sensitive teeth can usually whiten comfortably when the course is planned around it.

Whitening may not be the right choice if your teeth stay painful despite these measures, if you have significant gum recession with exposed roots, or if a tooth has an underlying problem. In those cases we'll talk about treating the cause first, or about other ways to improve the colour of your teeth, such as composite bonding for individual teeth.

At our practice in Comely Bank, professional home whitening is from £450, including an assessment, custom trays and gel, with the fee confirmed in writing before you begin. If sensitivity has put you off whitening in the past, we're happy to talk it through at a dental examination.

Questions

This guide is general information, not a diagnosis. A dentist needs to examine you to say what is right for your teeth.